Definitions for Volume Table Of Contents
volume table of con·tents

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1. Volume Table of Contents

   In the IBM System/360 storage architecture, the Volume Table of Contents (VTOC), is a data structure that provides a way of locating the data sets that reside on a particular DASD volume. With the exception of the IBM Z compatible disk layout in Linux on Z, it is the functional equivalent of the MS/PC DOS File Allocation Table (FAT), the Windows NT Master File Table (MFT), and the equivalent structure in, e.g., a Linux file system. The VTOC is not used to contain any IPLTEXT and does not have any role in the IPL process, therefore does not have any data used by or functionally equivalent to the MBR. It lists the names of each data set on the volume as well as size, location, and permissions. Additionally, it contains an entry for every area of contiguous free space on the volume. The third record on the first track of the first cylinder of any DASD (e.g., disk) volume is known as the volume label and must contain a pointer to the location of the VTOC. The location of the VTOC may be specified when the volume is initialized. For performance reasons it may be located as close to the center of the volume as possible, since it is referenced frequently. A VTOC is added to a DASD volume when it is initialized using the Device Support Facilities program, ICKDSF, in current systems. When in OS/360 and successors allocates a data set, it generally searches the catalog to determine the volumes on which it resides. When a program opens a Direct Access Storage Device (DASD) dataset, the OPEN routine searches the VTOC index (VTOCIX) if there is one, or directly searches the VTOC if there is no VTOCIX.

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1. Volume table of contents

   In the IBM mainframe storage architecture, Volume Table Of Contents, or VTOC, is a data structure that provides a way of locating the data sets that reside on a particular disk volume. It can reside within the first 64K tracks on the volume, and lists the names of each data set on the volume as well as size, location, and permissions. Additionally, it contains an entry for every area of contiguous free space on the volume. The third record on the first track of the first cylinder of any volume of DASD is known as the volume label and must contain a pointer to the location of the VTOC. A VTOC is added to a disk when it is initialized using the Device Support Facilities utility program, ICKDSF. VTOC was originally designed for removable disk packs. To locate a data set, a program will generally interrogate a z/OS catalog to find the volume where the data set resides. Having found the correct volume, the VTOC is searched to find out where on the disk the data set is stored. The VTOC comprises records known as Data Set Control Blocks, or DSCBs. There are ten types of DSCB. The first DSCB in the VTOC is always a format 4 DSCB which describes the VTOC itself and attributes of the disk volume on which this VTOC resides. The second DSCB is always a format 5 DSCB which describes free space within the VTOC. Normally, the rest of the VTOC will contain format 0 DSCBs, which are empty entries, and format 1 or format 3 DSCBs, which describe the "extents" of data sets, giving their start address and end address of up to 16 such "extents" on disk. The initial part of a data set is described by a format 1 DSCB. If necessary, format 3 DSCBs are used to describe further "extents" of the data set. When a data set is deleted, its format 1 DSCB is overwritten to become a format 0 DSCB, and the format 3 DSCB, if one exists, is similarly deleted.

How to pronounce Volume Table Of Contents?

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How to say Volume Table Of Contents in sign language?

Numerology

1. Chaldean Numerology

   The numerical value of Volume Table Of Contents in Chaldean Numerology is: 7

2. Pythagorean Numerology

   The numerical value of Volume Table Of Contents in Pythagorean Numerology is: 7

References

1. ^ Wikipedia
   https://en.wikipedia.org/wiki/Volume_Table_of_Contents
2. ^ Wikidata
   https://www.wikidata.org/w/index.php?search=Volume Table Of Contents